There are some code issues with the toolbars at the moment. Much of that comes from trying to synchronize correctly with the standard themeing mechanisms. The good new is that it means *if* users have icons for all the art stuff extras, then they will show up in Inkscape.

In theory, the icon preview should show you the results at different sizes. It is using the same code used to generate the actual bitmaps for the toolbars, etc. The main trick there is that different users have different sizes for things, so you might need to play a bit to get them happy for all. In the long run we are pushing for an official SVG way to have multiple versions in a single file that switch based on target display resolution.

Also for the names, there was an effort started to collect up all the names commonly used by art programs but not yet in the standard sets. It would be helpful to review that and suggest any changes, additions, etc. needed.